From MegKF:

Kyouhei is a boxer, training to become world champ. He has a dark past. Yuuya is a chef, or was until Kyouhei got him so riled up he slugged him on the job and was fired. Minami *shivers happily* is this super-gorgeous boy who once trained with Kyouhei's, though they also have bad blood in the past, and are now rivals.

Tsukasa Miyu's life revolved around only one thing--swimming. She gets admitted to Tenkai Academy on a swimming scholarship. However, before the start of high school, she encounters Suzuki Aoi and gets drawn into a world that doesn't involve just swimming anymore...

Welcome to Rubbers 7, a small Japanese convenience store with a reputation for some odd owners. Rumors of mob connections and one rather eccentric boss with a passion for Ping-pong tend to keep business low. But when a young, quiet girl is framed for shoplifting and ends up working for the store. Can her touch, with the help of her unusual coworkers, including a shy boy and a drag queen, turn the fortune of the store around?

The Achiga Girls' Academy in Nara once defeated regional mahjong powerhouse Bansei High School. It advanced into the national team semifinals but lost to the eventual champion, and the mahjong club was later disbanded. Six years later, elementary school student Shizuno Takakamo befriends transfer student Nodoka Haramura. The two eventually enter Achiga Girls', but Nodoka transfers out of the school in the second year. When Shizuno sees Nodoka on television the following year as the national middle school individual mahjong champion, she decides to revive Achiga's mahjong club.

Yutaka works as a trainer at his father's boxing gym. In a dark alley one day, he runs into Kei, who fights off several thugs. Trying to help a young delinquent get off the street, Yutaka invites Kei to the gym. But Kei is no ordinary delinquent...

In the series:
Vol. 1 - 白い獣の、聞こえぬ声の、見えない温度の、 Shiroi Kemono no, Kikoenu Koe no, Mienai Ondo no,

Vol. 2 - 赤い桎梏の、約束の場所の、望んだ十字架の、Shikkoku no, Yakusoku no Basho no, Nozonda Juujika no,

Sam is a young boy in Thailand. Not like other kids who can play happily, Sam has to train everyday at a Thai Boxing gym because when he was small his parents sold him to that gym for money. Everyday Sam undergoes a tough training. But Sam also has a wish. To become a champion so he can taste a happy life. It sounds impossible but a few years later due to an accident he finally gets the chance to meet the champion, who also happens to be his idol !!

Haruki Ootori, Misaki FC's untouchable ace, poured all his passion into looking cool. However, transfer student Kaoru Jinmyou beat him hollow at soccer, his specialty. Having met his first defeat, Haruki challenges Kaoru to a rematch, and...!?

Shoubu wa Toki no... Un Daro? is actually a series which Takaguchi co-writes with another artist. SEVEN is a solo work using many of the same characters, but takes place slightly later. It is about the members of the basketball team at a sports-based high school.
The first chapter focuses on a new character, Kiyoshi. Although he is attending a sports-based school, he is unable to play sports because of a childhood accident. He isn't dealing well, until Nana (Seven) takes him under his wing and asks him to be the manager of the club.
Nana is a senior and captain of the basketball team. Kiyoshi quickly falls for him. But most of Nana's attention is focused on his coach, Saegusa. The man practically built the basketball team from scratch and was manager at one point. He played basketball in middle school, but fell prey to some kind of chronic illness and wasn't able to play after that. All his life he worked with the goal that he would one day be able to play again. But suddenly, he realizes that it will never happen. He begins drinking and becomes depressed. Nana works to pull him out of it, and perhaps they grow too close...
from Tranlated Treasures

From Beautiful Soup:

Hokuto is a first year student at a famous athletic school... however, he doesn't happen to play any sports due an anxiety problem that he had developed. Now, after being pressured by his friend Yuri, he has become the manager of the basketball club. Strange things start to develop as he gets harassed by some of his senpai and begins to battle some demons...

Toshihiko Tanaka is a boy who entered Kakegawa High School with his friends Kenji & Kazuhiro, in order to play soccer with Yoshiharu Kubo, a great soccer player whom they have idolized. While his other two friends were reluctant to play again, "Toshi" eventually convinces them to play for the team. The team soon find themselves in the midst of a quest to the All-Japan High School Championship, while overcoming obstacles along the way.

Two childhood friends, Noboru and Anne, grow up in France and love cycling. Noboru has never beaten Anne in a race. One day Noboru has to return to Japan. Noboru and Anne make a promise to meet in the Tour de France as professional cyclists for their respective countries. A story of Noboru's struggle to fulfill that promise. The oneshot appeared in 2017 issue 19 of Weekly Shounen Jump.

Takumi and Kishou are childhood friends. Both are in the archery club. But then, Takumi gets injured. Because he can't do archery anymore, he becomes the archery club manager.
For years, Kishou has liked Takumi as more than a friend. But he's afraid that Takumi won't accept that, so he tries to break up their friendship...?!

Taken from ryColaa Scanlations:

Meet Abo Ozawa, ace pitcher. He can’t seem to make up his mind, on or off the baseball diamond. Off the field, he finds himself pulled in either direction by two lifelong friends. On one hand, there is the cute-but-fiery Hana Eguchi, who’s also an ace pitcher, even more famous, and constantly assaulted by reporters and talent scouts. There’s just no controlling this girl. On the other hand, there is the cute-but-controlled Noriko “Norippe” Asai. The third member of the trio, she finds herself overshadowed by her two friends. As events unfold, will he be able to choose between them?

But Abo’s mind is on baseball, and he doesn’t have time to deal with these problems. Or does he? On the pitcher’s mound, on the one hand, his left arm has the control to put the ball right where he wants to with absolutely perfect precision. And on the other hand, his right arm is a powerful uncontrolled monster that flails fireballs at the plate too fast to see. Which glove should he wear?

On or off the field, he is faced with the decision: right vs. left? In the end, will he be able to choose?

From Fantasyshrine:

Ritsuro is an expert in surfing and sex but a novice in love. As fate would have it, he meets another novice in both love and surfing. On the Shonan* beach, these two novices actually fell in love... with each other... But will their love survive from all the confusion, hurt, and growing up? A legend of love among surfers!

(*Shonan: a leading resort area in central Japan famous for surfing, sail-boating, and water sports)

+ One-shot: Hold me Tight
Jinno is suffering from a stomach cancer and lost his will to live, His doctor revived him once, can he do it again?

Four youths with completely different personalities under Coach Shen’s training become a team of amazing swimmers. The life of these four are about to begin!

A oneshot from Fellows 2009-08.

Volume 1
1) Takaramono
Naoyuki, a sincere and honest country boy comes to Tokyo for high school and stays with his cousin's family. At first everybody takes advantage of him, thinking that he's too naive to catch on. His cousin Satoshi, who's in college, is no different. He demands that Naoyuki have sex with him in exchange for tutoring him... In no time, despite his less than honourable initiate intention, Satoshi starts falling in love with the pure-hearted boy.

2) Kimochi no Yukue
Oneshot also found in Koibito no Namae.

3) Melody
Futuristic Sci-fi story about a singer and an android that was abandoned. Not scanlated.

4) Afterword

Volume 2
1-2) Takaramono

3) Afterword

Volume 3
1) Takaramono

2) Kimi to Konomama
Tells of a tragic love story between a boxer with an incurable illness and his loyal fan. Not scanlated.

3) Takaramono EX

4) Afterword

Volume 4
1) Takaramono

2) Kimi ni Ai ni
An exchange student from Britain suddenly proclaims his love for his Japanese classmate and goes on the offence. Oneshot also found in Saikou no Kimi.

3) Yakusoku
AKA Promise, also found in Koibito no Jikan.

4) Afterword


Note: June's versions do not include any of the unrelated one-shot stories.

From MegKF:

1-2) Tatoeba Sore Wo Koi To Yobunar
Nobuki is in love with Toomu but doesn't tell him. After an incident Nobuki finally confesses his feelings to Toomu, but Toomu doesn't know what his feelings for Nobuki is.

3-4) Triangle Blue
Haruki is looking for work when his friend Rei reccomends he works at a host club with him.

5) Haru was injured forcing him to stop playing tennis the sport he loves while Eiji his kouhai tries to rekindle the passion the inspired him to play tennis.

6) Negishi is convinced that he can keep his sensei out of trouble but does he realy know what he is doing.

Midorikawa is indifferent in love, but yet she is dating Nonomiya. As she starts dating him, she may, or may not fall in love...